<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div id="test"></div>

  <script type="text/javascript" src="../js/react.development.js"></script>
  <script type="text/javascript" src="../js/react-dom.development.js"></script>
  <script type="text/javascript" src="../js/babel.min.js"></script>
  <script type="text/javascript" src="../js/prop-types.js"></script>
  <script type="text/babel">
    class Demo extends React.Component{
        myRef = React.createRef()
        myRef2 = React.createRef()
        showData=()=>{
            alert(this.myRef.current.value)
        }
        showData2=(event)=>{
            alert(event.target.value)
        }
        render(){
            return (
                <div>
                    <input ref={this.myRef} type="text" placeholder='点击按钮提示数据'/>&nbsp;
                    <button onClick={this.showData}>点我提示左侧数据</button>&nbsp;
                    <input onBlur={this.showData2} type="text" placeholder='失去焦点提示数据'/>
                </div>
            )
        }
    }
    ReactDOM.render(<Demo/>,document.getElementById('test'))
  </script>
</body>

</html>